Comparative effects of RRR-alpha- and RRR-gamma-tocopherol on proliferation and apoptosis in human colon cancer cell lines

BACKGROUND: Mediterranean societies, with diets rich in vitamin E isoforms, have a lower risk for colon cancer than those of northern Europe and the Americas. Vitamin E rich diets may neutralize free radicals generated by fecal bacteria in the gut and prevent DNA damage, but signal transduction activities can occur independent of the antioxidant function. The term vitamin E represents eight structurally related compounds, each differing in their potency and mechanisms of chemoprevention. The RRR-γ-tocopherol isoform is found primarily in the US diet, while RRR-α-tocopherol is highest in the plasma. METHODS: The effectiveness of RRR-α- and RRR-γ-tocopherol at inhibiting cell growth and inducing apoptosis in colon cancer cell lines with varying molecular characteristics (SW480, HCT-15, HCT-116 and HT-29) and primary colon cells (CCD-112CoN, nontransformed normal phenotype) was studied. Colon cells were treated with and without RRR-α- or RRR-γ-tocopherol using varying tocopherol concentrations and time intervals. Cell proliferation and apoptosis were measured using the trypan blue assay, annexin V staining, DNA laddering and caspase activation. RESULTS: Treatment with RRR-γ-tocopherol resulted in significant cell death for all cancer cell lines tested, while RRR-α-tocopherol did not. Further, RRR-γ-tocopherol treatment showed no cytotoxicity to normal colon cells CCD-112CoN at the highest concentration and time point tested. RRR-γ-tocopherol treatment resulted in cleavage of PARP, caspase 3, 7, and 8, but not caspase 9. Differences in the percentage cell death and apoptosis were observed in different cell lines suggesting that molecular differences in these cell lines may influence the ability of RRR-γ-tocopherol to induce cell death. CONCLUSION: This is the first study to demonstrate that multiple colon cancer cell lines containing varying genetic alterations will under go growth reduction and apoptosis in the presence of RRR-γ-tocopherol without damage to normal colon cells. The amount growth reduction was dependent upon the molecular signatures of the cell lines. Since RRR-γ-tocopherol is effective at inhibition of cell proliferation at both physiological and pharmacological concentrations dietary RRR-γ-tocopherol may be chemopreventive, while pharmacological concentrations of RRR-γ-tocopherol may aid chemotherapy without toxic effects to normal cells demonstrated by most chemotherapeutic agents

Search for W~1Z~2\widetilde{W}_1\widetilde{Z}_2 Production via Trilepton Final States in ppˉp\bar{p} collisions at s=1.8\sqrt{s}=1.8 TeV

We have searched for associated production of the lightest chargino, $\widetilde{W}_1$, and next-to-lightest neutralino, $\widetilde{Z}_2$, of the Minimal Supersymmetric Standard Model in $p\bar{p}$ collisions at \mbox{$\sqrt{s}$ = 1.8 TeV} using the \D0 detector at the Fermilab Tevatron collider. Data corresponding to an integrated luminosity of 12.5$\pm 0.7$ \ipb were examined for events containing three isolated leptons. No evidence for $\widetilde{W}_1\widetilde{Z}_2$ pair production was found. Limits on $\sigma(\widetilde{W}_1\widetilde{Z}_2)$Br$(\widetilde{W}_1\to l\nu\widetilde{Z}_1)$Br$(\widetilde{Z}_2\to l\bar{l}\widetilde{Z}_1)$ are presented.Comment: 17 pages (13 + 1 page table + 3 pages figures). 3 PostScript figures will follow in a UUEncoded, gzip'd, tar file. Text in LaTex format. Submitted to Physical Review Letters. Replace comments - Had to resumbmit version with EPSF directive

Second Generation Leptoquark Search in p\bar{p} Collisions at s\sqrt{s} = 1.8 TeV

We report on a search for second generation leptoquarks with the D\O\ detector at the Fermilab Tevatron $p\bar{p}$ collider at $\sqrt{s}$ = 1.8 TeV. This search is based on 12.7 pb$^{-1}$ of data. Second generation leptoquarks are assumed to be produced in pairs and to decay into a muon and quark with branching ratio $\beta$ or to neutrino and quark with branching ratio $(1-\beta)$. We obtain cross section times branching ratio limits as a function of leptoquark mass and set a lower limit on the leptoquark mass of 111 GeV/c$^{2}$ for $\beta = 1$ and 89 GeV/c$^{2}$ for $\beta = 0.5$ at the 95%\ confidence level.Comment: 18 pages, FERMILAB-PUB-95/185-

Characterization of the Bacterial Diversity of the Fruit Carposphere

Specialty crop horticulture is a multi-billion-dollar industry in the United States. Everyone has eaten an apple, orange, peach, or melon at some point in their life. In 2020, domestic production alone produced 5 million tons of apples in the United States, whereas melons brought in 2.7 million tons. However, little research has been done at the point of harvest characterizing their surface bacterial composition. Understanding these surface bacteria on fruits is critical for the food industry, growers, processors, as well as the consumer. Characterizing the carposphere microbiome of tree fruit like apples, peaches, and oranges or ground fruit like melons at point of harvest can inform the fruit industry in making decisions on post-harvest processing and storage procedures. The overall goal of these studies was to characterize the bacterial diversity and composition of different fruit carpospheres at the point of harvest to gain a better understanding of the fruit microbiome entering post-harvest. Whole fruits were sampled at point of harvest in the United States and 16S rRNA gene amplicon sequencing was conducted to characterize the bacterial diversity. Apples, oranges, and peaches had bacterial communities that clustered by the season and the harvesting point in the growing season that they were collected. Beta-dissimilarity of apple carpospheres had bacterial communities that were nested over the harvesting points, while orange carpospheres had bacterial communities that were nested and turning over consistently. Lastly, peach carposphere had bacterial communities that were turning over at each harvesting point. Melons that were collected from different regions around the United States, showed differences in bacterial diversity based on region of growth and less on type of melon or netting of melon rind. The two main agricultural growing regions, Arizona, and California, exhibit bacterial turnover and bacterial nestedness for netted melons over the four years sampled, respectively. This study lays the foundation for the produce industry to have a better understanding of the bacteria entering post-harvest processing to eventually improve methods that will impact food safety, storage time, and fruit quality

The annexin V/propidium iodide double staining assay following 100 μM tocopherol treatment in HCT-116 cells (Panels A-D) for 24 hours and SW480 (Panels E-H) cells for 70 hours

<p><b>Copyright information:</b></p><p>Taken from "Comparative effects of RRR-alpha- and RRR-gamma-tocopherol on proliferation and apoptosis in human colon cancer cell lines"</p><p>BMC Cancer 2006;6():13-13.</p><p>Published online 17 Jan 2006</p><p>PMCID:PMC1379650.</p><p>Copyright © 2006 Campbell et al; licensee BioMed Central Ltd.</p> These data show RRR-γ-tocopherol is superior to RRR-α-tocopherol at inducing apoptosis. The percentages in right quadrants represent percentage apoptosis over the blank and are an average of at least two independent trials

Western Blot analysis of SW480 (left) and HCT-116 (right) cell lysates following treatment with 100 μM tocopherols for 24 hours blotted with the antibodies to caspase 3, caspase 7, caspase 8, PARP, and β-actin as a loading control

<p><b>Copyright information:</b></p><p>Taken from "Comparative effects of RRR-alpha- and RRR-gamma-tocopherol on proliferation and apoptosis in human colon cancer cell lines"</p><p>BMC Cancer 2006;6():13-13.</p><p>Published online 17 Jan 2006</p><p>PMCID:PMC1379650.</p><p>Copyright © 2006 Campbell et al; licensee BioMed Central Ltd.</p

Growth curves for SW480 cells (A) HCT-116 cells (B), HCT-15 cells (C), HT-29 (D) were plotted as average cell counts over time after treatment with 100 μM tocopherol at 1, 2, and 3 days

<p><b>Copyright information:</b></p><p>Taken from "Comparative effects of RRR-alpha- and RRR-gamma-tocopherol on proliferation and apoptosis in human colon cancer cell lines"</p><p>BMC Cancer 2006;6():13-13.</p><p>Published online 17 Jan 2006</p><p>PMCID:PMC1379650.</p><p>Copyright © 2006 Campbell et al; licensee BioMed Central Ltd.</p> and Live Cell Counts in CCD-112CoN cells following 100 μM tocopherol treatment at 72 hours (E). Values plotted are averages of three independent trials. Error bars represent standard deviation of the means. Positive controls used included (15 deoxy Δ 12,14 PGJ2, troglitzone and camptothecin). (Data are representative of three independent trials performed in triplicate. *p < 0.05 vs. vehicle at corresponding concentration.

SW480, HCT-116, and HT-29 cells were treated for 5 hours with varying concentrations of tocopherol or the PPAR γ ligand, troglitazone (positive control)

<p><b>Copyright information:</b></p><p>Taken from "Comparative effects of RRR-alpha- and RRR-gamma-tocopherol on proliferation and apoptosis in human colon cancer cell lines"</p><p>BMC Cancer 2006;6():13-13.</p><p>Published online 17 Jan 2006</p><p>PMCID:PMC1379650.</p><p>Copyright © 2006 Campbell et al; licensee BioMed Central Ltd.</p> The percent of dead cells for SW480 cells (A), HCT-116 cells (B) or HT-29(C) was measured using the Live-Dead assay (Molecular Probes, CA). (Data are representative of three independent trials performed in triplicate. *p < 0.05 vs. vehicle at corresponding concentration.

Leptin-inhibited PBN neurons enhance responses to hypoglycemia in negative energy balance

Hypoglycemia initiates the counter regulatory response (CRR), in which the sympathetic nervous system, glucagon, and glucocorticoids restore glucose to appropriate concentrations. During starvation, low leptin restrains energy utilization, enhancing long-term survival. To ensure short-term survival during hypoglycemia in fasted animals, the CRR must overcome this energy-sparing program and nutrient depletion. Here, we identify in mice a previously unrecognized role for leptin and a population of leptin-regulated neurons that modulate the CRR to meet these challenges. Hypoglycemia activates leptin receptor (LepRb) and cholecystokinin (CCK)-expressing neurons of the parabrachial nucleus (PBN), which project to the ventromedial hypothalamic nucleus. Leptin inhibits these cells and Cck(cre)-mediated ablation of LepRb enhances the CRR. Inhibition of PBN LepRb cells blunts the CRR, while their activation mimics the CRR in a CCK-dependent manner. PBN LepRb(CCK) neurons represent a crucial component of the CRR system, and may represent a therapeutic target in hypoglycemia